• Corrections as provided in Section 42:
A tax payer has the duty to correct the tax base or tax amount in the following circumstances: in the case of cancellation or refund of the whole, or part, of the taxable supply; in the case of a decrease or increase of the tax base, based on the conditions agreed after the date of taxable supply; in the case of the return of excise duty, if the goods were not delivered; in the case of the return of a payment from which the taxpayer was obliged to pay tax at the date of its receipt, and if the taxable supply did not actually occur, and also if the payment was used to cover another taxable supply.
• Corrections as provided in Section 43:
This deals with cases where the tax payer has paid the wrong amount of tax. In cases where the tax payer has paid too much tax in error (e.g. if tax was applied in the case of a tax-exempt transaction), corrections are possible; in cases where the tax payer has paid too little tax in error, however, he has until the end of the month following the month in which the mistake was discovered to correct it.